Denver Broncos quarterback Peyton Manning (18) at the line of scrimmage against the Philadelphia Eagles in the third quarter at Sports Authority Field at Mile High. / Ron Chenoy, USA TODAY Sports

by Lindsay H. Jones and Jim Corbett, USA TODAY Sports

by Lindsay H. Jones and Jim Corbett, USA TODAY Sports

Now that Week 4 is over, it's time to take a look at where the NFL stands with one-quarter of the regular season over.

Oh, look (yawn), the Denver Broncos and New England Patriots are unbeaten in the AFC. Are we headed for another showdown between Peyton Manning and Tom Brady as they battle for a Super Bowl berth -- and the title of best of all time?

AFC EAST

New England Patriots (4-0): B+

It's hard to beat being 4-0, but it hasn't been easy for the Patriots to get here, with ugly wins against Buffalo and the New York Jets in Weeks 1 and 2. But quarterback Tom Brady is leading an improving offense that should only get better when receiver Danny Amendola and tight end Rob Gronkowski are cleared to play. Cornerback Aqib Talib has emerged as a defensive star, but the Patriots now must figure out how to deal with the loss of star defensive tackle Vince Wilfork.

Miami Dolphins (3-1): B

The Dolphins suffered their first loss Monday night â?? and it was a bad one. They were blown out of the Superdome by the New Orleans Saints. But the rest of the first quarter of the season was a good one, with positive development from second-year quarterback Ryan Tannehill.

New York Jets (2-2): C

Considering all of the drama and dysfunction around Florham Park, N.J., in the off-season, two wins in the first four games should be considered a success. Rookie quarterback Geno Smith is enduring his growing pains while surrounded by a mediocre group of talent. The Jets' defense, meanwhile, is ranked in the top 10 in several major categories â?? exactly what a young quarterback needs to stay in close games. Now if he can just reduce the turnovers ...

Buffalo Bills (2-2): B

Few teams are getting as much out of their draft picks early this season as the Bills, with first-round pick quarterback EJ Manuel (five touchdown passes), second-round pick Robert Woods (two touchdown catches) and third-round pick linebacker Kiko Alonso (four interceptions).

AFC NORTH

Baltimore Ravens (2-2): C

These Baltimore Ravens don't look much like the team we saw hoisting the Lombardi Trophy in February. With so much roster turnover, some troubles were to be expected, but the Ravens have yet to produce a dominant pass rush with the duo of Terrell Suggs and free-agent addition Elvis Dumervil. Franchise quarterback (and Super Bowl MVP) Joe Flacco has hardly been super â?? especially when he threw a career-high five interceptions in a Week 4 loss to Buffalo. The Ravens, if they can stay off the party bus, have plenty of work to do to return to their postseason form.

Cleveland Browns (2-2): B

The Browns earn a better-than-average grade for the way they proved just about everyone else in the NFL wrong by winning the past two games since trading away 2012 first-round pick running back Trent Richardson for a 2014 first-rounder. It was a move many saw as waving a white flag on 2013, while setting up to take a quarterback in next year's draft. Well, backup quarterback Brian Hoyer (who replaced an injured Brandon Weeden) and tight end Jordan Cameron had other plans, sparking wins against the Minnesota Vikings and Cincinnati Bengals.

Cincinnati Bengals (2-2): C

Of the three 2-2 teams in the division, the Bengals have to be the biggest disappointment â?? and also the biggest enigma. How, really, can you explain scoring 34 points to beat the Packers one week, and scoring only six points in a loss to the Browns the next? This should be the season the Bengals, a wild-card team the past two years, sees significant maturation from their corps of young players, including QB Andy Dalton. But it hasn't happened yet, at least not consistently.

Pittsburgh Steelers (0-4): F

Quarterback Ben Roethlisberger called the Steelers the worst team in the league after Pittsburgh's loss to the Minnesota Vikings in London last weekend. He might not have watched any Jacksonville tape lately, but 0-4 must feel worse in Pittsburgh than just about anywhere else. Only once since Roethlisberger arrived in 2004 have the Steelers been below .500, let alone winless through four games. There doesn't appear to be an easy fix, either, with an aging defense, a subpar running game and a makeshift offensive line.

AFC SOUTH

Indianapolis Colts (3-1): A

No sophomore slump for Andrew Luck. Thanks to a new, but familiar, offensive coordinator, Luck, the 2012 No. 1 overall pick, continues to improve. The Colts had an early statement win at San Francisco in Week 3. But the biggest test for Luck and the young Colts comes this week with a game against the Seahawks in Indianapolis. Luck vs. Russell Wilson â?? can't ask for a better early-season storyline than that.

Tennessee Titans (3-1): A

The Titans were an overtime loss to Houston away from 4-0 after finally getting the type of play out of quarterback Jake Locker they had been hoping for when they drafted him in the first round in 2011. Tennessee faces a major challenge, though, moving into the second quarter of the season without Locker, who suffered a serious hip injury in a Week 4 against the Jets. Can they keep the momentum with backup Ryan Fitzpatrick?

Houston Texans (2-2): C

There is unrest in Houston after quarterback Matt Schaub threw his third interception for a touchdown (in consecutive games) in an overtime loss to Seattle, Houston's second consecutive loss. Players are angry. Fans are angry. This is a team that expects to be much better than a .500 team â?? and certainly has the talent to be one of the best teams in the AFC. The Texans can get back on track Sunday against another borderline desperate team â?? the San Francisco 49ers.

Jacksonville Jaguars (0-4): F

Giving this team an F almost feels like kicking it when it's down. But how can the Jaguars' start be described as anything but a disaster? Jacksonville has scored only 31 points in four games â?? that's barely more than a touchdown a game. The Jaguars should look forward to Sunday's game against floundering St. Louis, because Week 6 brings a road game at Denver that could feature the largest Las Vegas point spread in NFL history.

AFC WEST

Denver Broncos (4-0): A

How many superlatives are left for how Peyton Manning and the Broncos' offense are carving up opponents through the first quarter of the season? At 37, with a surgically repaired neck, Manning is in the midst of perhaps the best stretch of games of his career, with 16 touchdown passes and no interceptions. The Broncos are scoring more than 44 points per game, even without marquee left tackle Ryan Clady, who has been lost for the year. More impressively, perhaps, is how the Broncos barely noticed the absence of star pass rusher Von Miller (suspension) or cornerback Champ Bailey (foot injury) in any of their early games.

Kansas City Chiefs (4-0): A

The Kansas City Chiefs have already doubled their win total from 2012 in what has to be one of the league's best storylines of the season. The Andy Reid-Alex Smith partnership is working even better than they could have predicted, and the Chiefs defense is for real. That front seven, with pass rushers Tamba Hali and Justin Houston and nose tackle Dontari Poe, is going to make many offensive lines look silly.

San Diego Chargers (2-2): B

The San Diego Chargers managed to rebound well from what could have been a devastating Week 1 collapse on Monday Night Football, but in beating the Philadelphia Eagles and Dallas Cowboys, in their second and fourth games respectively, the Chargers have shown progress from the Norv Turner Era. In Sunday's win against Dallas, quarterback Philip Rivers, in a make-or-break season, played his best game in years â?? that's almost worth an A grade alone. Almost.

Oakland Raiders (1-3): D

The Raiders have not kept pace with the rest of the improving AFC West, though there have been some bright moments in the first month, thanks to the scrambling of quarterback Terrelle Pryor and the creative blitzes called by defensive coordinator Jason Tarver. The Raiders' only win so far is against Jacksonville, and the Raiders and Pryor, recovering from a concussion, will need to improve quickly to avoid being lapped by the rest of the division by midseason.

****

****

Pete Carroll's Seattle Seahawks have announced themselves as the NFC's team to beat with the first 4-0 start in franchise history, but the Saints are back to normal at 4-0, too. As for the once-mighty NFC East, epitomized by the reeling, 0-4 New York Giants, consider that the division is a combined 1-7 against the AFC West.

NFC East

Dallas Cowboy (2-2): C

Who are these guys? Coach Jason Garrett was stripped of his play-calling duties and offensive coordinator/line coach Bill Callahan was supposed to run his offense through tailback DeMarco Murray. But with the exception of Murray's 176-yard game against the St. Louis Rams, the Cowboys are still built around QB Tony Romo, which means riding the up-and-down "Romocoaster.''

Philadelphia Eagles (1-3): D

So much for revolutionizing the league. Since that impressive 33-27 opening-night victory over the Washington Redskins by Chip Kelly's blur offense, the Eagles have lost three straight because their defense can't stop anybody. They sorely miss play-making receiver Jeremy Maclin, who was lost to a season-ending knee injury in training camp.

Washington Redskins (1-3): D

The Redskins go into their bye week off a sorely needed Week 4 comeback win over the Oakland Raiders. Robert Griffin III, coming off knee surgery, has played better in each start, though probably not improving fast enough for fans. Now tailback Alfred Morris needs the bye week to allow his bruised ribs to heal. The schedule gets tough, with Dallas, Chicago and Denver up next.

New York Giants (0-4): F

This once-proud franchise, which has won two of the last six Super Bowls, has been outscored 146-61 and is now lumped at the bottom of the league with the winless Pittsburgh Steelers, Tampa Bay Buccaneers and Jacksonville Jaguars. The offensive line is an aging, injury-depleted sieve, running back David Wilson has been a liability protecting the football, and quarterback Eli Manning is struggling. Offensive coordinator Kevin Gilbride needs to readjust the down-field passing game to help Manning.

NFC NORTH

Detroit Lions (3-1): B

RB Reggie Bush has made all the difference for a surprise contender that won just four games last season while relying too heavily on Matthew Stafford, who threw a league-high 727 times. A more diversified offense no longer is dependent solely on the Stafford-to-Calvin Johnson connection. DT Ndamukong Suh is living up to expectations as a pass-rushing force, helped by first-round DE Ziggy Ansah, who hasn't looked like a rookie.

Chicago Bears (3-1): B

Jay Cutler, Mr. Fourth Quarter, reverted to the reckless gunslinger with four turnovers in a Week 4 loss to the Detroit Lions. Until then, coach Marc Trestman had done a good job of getting Cutler to buy into his quick-rhythm passing game. The defense has been living on the edge by relying on turnovers, and when the Bears haven't gotten them, they've been gashed by the likes of A.J. Green, Antonio Brown and Reggie Bush.

Green Bay Packers (1-2): C

As poorly as the Packers have played, they're just two games behind the division-leading Bears and Lions. Injuries and an offensive line suspect at the edges have caused issues. But despite a costly Week 3 fumble, the Packers might have found an answer to their long-dormant run game -- rookie Johnathan Franklin, who cranked out 126 yards on 16 touches in a Week 3 loss to Cincinnati.

Minnesota Vikings (1-3): D

Did Matt Cassel just invite a quarterback controversy to the Vikings' bye week? Coach Leslie Frazier insists that the maddeningly inconsistent Christian Ponder remains his quarterback, though Cassel did what Ponder hasn't â?? sparked his team by throwing down the field in a 34-27 win Sunday against Pittsburgh in London. The defense has pressured quarterbacks, with 14 sacks entering the bye week.

NFC SOUTH

New Orleans Saints (4-0): B+

Everyone expected the Saints would get back to winning with coach Sean Payton's return from a year-long suspension. But defensive coordinator Rob Ryan has been the assistant coach of the season so far. Rookie safety Kenny Vaccaro, defensive tackle Akiem Hicks and end Cameron Jordan have been studs. And QB Drew Brees keeps stringing 300-yard games. Tight end Jimmy Graham, with two TDs on Monday night, is having a monster season in a contract year.

Carolina Panthers (1-2): C

QB Cam Newton is playing better, with six touchdown passes (another on the ground) and just two interceptions. DeAngelo Williams is running strong again. It helped that offensive coordinator Mike Shula unveiled the read-option in Carolina's 38-0, Week 3 pummeling of the Giants. The defense is stouter in the interior given the strong play of draft picks Star Lotulelei and Kawann Short.

Atlanta Falcons (1-3): D

It wasn't supposed to be this way, but injuries have robbed the Falcons of defensive end Kroy Briermann (for the season) and linebacker Sean Weatherspoon (injured reserve/designated to return Sept. 17). Running back Steven Jackson is likely to miss another couple of weeks with a thigh bruise, while receiver Roddy White has been limited by a high ankle sprain. Unlike last season, QB Matt Ryan has not been able to bail the Falcons out of close games.

Tampa Bay Buccaneers (0-4): F

Smothered in controversy, the season could spiral out of control at any moment. QB Josh Freeman, benched for rookie Mike Glennon, wants out -- now. And coach Greg Schiano and GM Mark Dominik are trying to accommodate but can't find a taker for a guy with a big contract who will be a free agent at the end of the season. Freeman has become such a distraction that he wasn't allowed on the sideline Sunday. And now he's accusing someone in the organization of leaking confidential drug-test information.

NFC WEST

Seattle Seahawks (4-0): A

Cornerback Richard Sherman and the league's No. 1 scoring defense have earned the right to chatter away. QB Russell Wilson owns the league's top passer rating over the past 12 games, dating to last season. He can take over a game -- and he did when the Seahawks stormed back for a 23-20 overtime win Sunday at Houston. And Marshawn Lynch's bruising running helps keep that big-play defense stay fresh.

San Francisco 49ers (2-2): C

After torching the Packers for 412 passing yards in the opener, Colin Kaepernick encountered adversity for the first time, reminding everyone he's a quarterback with just 14 career starts. Defenses are forcing him to think by taking away his first option. After the first two-game losing skid of his 49ers coaching career, Jim Harbaugh got back to pounding Frank Gore against the Rams. Still, a vaunted defense won't be the same with the loss of pass-rushing linebacker Aldon Smith for an undetermined amount of time.

Arizona Cardinals (2-2): C

Their second-ranked run defense has kept them in games. But the run game hasn't gotten on track, and QB Carson Palmer has struggled to get in any kind of rhythm. In fact, coach Bruce Arians on Monday called the offense "putrid" and said he never has had a team take so long to learn his playbook. One play they should remember: Palmer to Larry Fitzgerald. The receiver has just three touchdowns.

St. Louis Rams (1-3): D

QB Sam Bradford still hasn't turned the corner with a supporting cast that simply isn't good enough. Jeff Fisher is a run-oriented coach with the league's worst run game. Robert Quinn and Chris Long have been bright spots for a middling defense.